Delayed Engagement

I was wondering if anyone else on this forum has experienced delayed transmission engagement while driving at low speeds. For example, I can be coasting 15-20 mph downhill, and upon pressing the gas pedal my revs climb to 1500-2000ish rpm and then it kicks into gear. Is this just the clunky torque converter or is this reason for concern? Does anyone else experience this issue? Thanks!

 

Yes and it’s annoying, even more so when you’re trying to cross two lanes of traffic to make a left turn or merging on a highway. I got a tune and it mostly fixed it.

 

Phew, thanks for the reply. I wanted to make sure that my transmission fluid wasn't low or even worse, burnt. I'm thinking about a tune soon.

 

If you have the shifter in a selected gear that isn't neutral or park, then your transmission should be in a gear and not disengaged. If you press the gas pedal and the engine rpm flares up without noticeable acceleration then you may be experiencing clutch slippage. If this is left unchecked, it will destroy the transmission. If you feel you are experiencing clutch slippage then I would take to the dealer as soon as possible to have it looked at.

 

Oh, ok. It may be even more dangerous than I was thinking at first. I'll get it checked out.

 

What is happening is almost identical to what is mentioned in post #7 in this thread: https://www.tacomaworld.com/threads/engine-revs-but-no-engagement-with-transmission.537618/

 

Before you panic: keep in mind that these trucks are part-time direct injected. This means the truck revs higher than most are used to and makes peak power around 3500 RPM. You mentioned coasting downhill. It may not be until 1500-2000 RPM before the engine even starts spinning fast enough to catch at those speeds. Not to mention the fact that, like most modern vehicles, these are computer controlled so in some ways they can be a little more delayed in response than older vehicles that had a physical connection between the gas pedal and engine.

 

I hadn't thought about that. Could it be that when coasting that it disengages and revs up to the same speed as the transmission (kind of like rev matching???) and that is what produces the effect?

 

It's possible. I'm not the most familiar with the inner workings of transmissions in general so I can't say for certain. It could just be in a lower gear due to the programming too.

 

Gotcha. I’ll do a little more research. Thanks!

 

This article may help understand the torque converter

https://www.google.ca/amp/s/www.motortrend.com/how-to/0808rc-torque-converters/amp/

As for the transmission. In gear ( either forward or reverse ) it will always have 2 clutches engaged. As it changes gear ratios it will dump one clutch and engage another, but outside of a shift ( which is fast and almost overlapping ) there will always be 2 clutches engaged regardless of throttle position or load.

There is one more clutch that engages that affects the torque converter, the lock up clutch. This engages typically at times of low load and throttle pedal to lock the flywheel and the input shaft together to improve fuel economy. I understand on the Tacoma that this can engage outside of these conditions. And can also be harsh in some trucks.

 

Just read through, it looks like it could be a hard engagement/dump of the clutch. I’m not sure what the solution would be in that case though. Does yours ever do this? Thanks!

 

Mine doesn't. It's possible that the fluid level is incorrect. I would take it to the dealer or a good shop have have the level checked.

 

Gotcha, thanks a bunch.